Crossword Puzzle Nail Structure CrosswordOnline version Test your knowledge on nail structure and growth. by Tonia Brooks 1 Protein that makes up nails and hair. 2 Protective layer at the base of the nail. 3 Area where nail cells are produced. 4 White, crescent-shaped area at the base of the nail. 5 Skin under the free edge of the nail. 6 Skin underneath the nail plate. 7 Living skin at the base of the nail plate. 8 Skin that surrounds the nail plate. 5 6 7 3 4 2 1 8